Polishing of discrete articles

ABSTRACT

Powder-filled capsules or other articles, to whose surface excess powder tends to adhere, are cleaned and polished by advancing them into the space between two juxtaposed disk-shaped elements one of which rotates in alternately opposite directions with respect to the other, moves towards and away from the surface of the other and tilts with respect to the other element. The articles are cleaned, that is the contaminating powder is removed from their surfaces, by frictional contact with the surfaces of the two elements. During movement of the articles towards and between the surfaces, and while the articles are between the surfaces of the elements, suction is maintained to remove loosened powder.

O Unlted States Patent [151 Wurst et al. 1 Mar. 7, 1972 [54] POLISHING OF DISCRETE ARTICLES 2,918,691 12/1959 Lake ..15l3.21

[72] Inventors: Helmut Wurst, Winnenden; H1118 FOREIGN A S 0 APPLCATIONS Kleinheppach, both of Germany 13,775 3/1899 Great Britain ..l34/6 1 Asslsnw qfira Wi lhl w 74: 24s 1/1956 Great Britain 134/21 8 Ge y w [22] Filed: Aug. 13, 1969 Primary Exandner-Morris 0. Wolk Assistam Examiner-Joseph T. Zatarga [21] Appl 849633 Attorney-Michael S. Striker [30} Foreign Application Priority Data [57] ABSTRACT Aug. 22, 1968 Germany ..P 17 82 374.4 Powder-filled capsules or other articles, to whose surface excess powder tends to adhere, are cleaned and polished by ad- [52] US- Cl. 15/21 C vancing them into the space between two disk- IHL A47] shaped elements one of which rotates in alternately opposite "134/6, 21, 25, 37, directions respect to the other moves and away 15/303 303, 21 21 C from the surface ofthe other and tilts with respect to the other element. The articles are cleaned, that is the contaminating [56] 1 Retem powder is removed from their surfaces, by frictional contact UNITED STATES PATENTS with the surfaces of the two elements. During movement of the articles towards and between the surfaces, and while the 48,814 7/1865 l-lotchklss et a1. ..l5/4 arti les ar b tween the surfaces of the elements, suction is 1,587,444 6/ 1926 Thomas 134/6 UX i t i t ve loo ened powder, 2,081,489 5/1937 Lisle et a1 ..l34/6 X Y 2,683,885 7/1954 Johnson ..l34/7 X 9 Claims, 2 Drawingflgures l as ,;z B-Q-ufl :ausar uznxnrnz c an: 2- I POLISHING 01F DISCRETE ARTICLES BACKGROUND OF THE INVENTION The present invention relates generally to the processing of discrete articles, and more particularly to the polishing of dis crete articles. Still more specifically, the present invention relates to a method of removing particulate contaminants from the surfaces of such discrete articles as powder-filled gelatin capsules or the like, and for an apparatus for carrying the method into effect.

It is frequently necessary to remove particulate contaminants from the surfaces of cylindrical, round, oval or similarly configurated articles. The invention will hereafter be described with respect to powder-filled capsules of hard gelatin, such as are used to accommodate medicine in pulverulent form. It is, however, not to be considered limiting to this particular application.

In manufacturing such capsules and filling them with the medication, it is impossible to avoid that the surface of the capsules is coated with some of the pulverulent medication. Depending on the type of powder and the substance of which it consists, the layer so deposited may adhere more or less firmly. Before such capsules are sold such contamination must evidently be removed. It was therefore customary heretofore to effect such removal manually, an undertaking which is not only time consuming but most expensive; it is evidently necessary to have personnel who carry out this work.

Attempts have been made to mechanize such cleaning operations. For this purpose it has become known to provide an apparatus which utilizes two endless belts with one stringer on each belt facing another stringer of the other belt. The capsules are introduced between the facing stringers of the belts and the latter advance in identical direction but one advances slightly faster than the other. The result is that while the capsules are advanced by the two stringers between which they are held, they simultaneously are turned because of the speed differential in the advancement of the two belts. However, this apparatus has been found less than satisfactory because the belts are quickly contaminated by the removed powder to the point where they are no longer capable of carrying out their intended function, that is removal of further powder from additional capsules. It is therefore necessary to frequently exchange the belts by removing the contaminated ones and replacing them with clean ones, and further to have the capsules pass repeatedly through the cleaning process. Evidently, this requires machine downtime for removal and replacement of the belts. In addition, the contaminated belts must be washed and dried and the latter process is quite time consuming so that it is necessary to keep a large quantity of replacement belts on hand. Finally, the apparatus of this type is rather large in its dimensions which is a disadvantage.

SUMMARY OF THE INVENTION The present invention has as its general object to overcome the aforementioned disadvantages.

More particularly the present invention has as its object to provide an improved method of polishing the surfaces of discrete articles.

An additional object of the invention is to provide an apparatus capable of carrying the novel method into effect.

A concomitant object of the invention is to provide such an apparatus which is relatively small in its dimensions, but is very simple in construction and therefore highly reliable.

Still another object of the invention is to provide such an apparatus which effects proper cleaning and polishing of the surfaces of the discrete articles with a single pass-through of the articles through the apparatus.

Still another object of the invention is to provide such an apparatus which requires only infrequent exchange of the polishing and cleaning elements.

In pursuance of the above objects, and others which will become apparent hereafter, one feature of the invention resides in a method of cleaning and polishing the surfaces of discrete articles for removing particulate contaminants therefrom. This method comprises the steps of advancing the articles in a predetermined path toward and beyond the processing station, and subjecting the articles to the influence of suction while they are in this path and thereby remove loose particulate contaminants. Finally, the articles are subjected at the processing station to a brushing action to thereby loosen particulate contaminants which adhere to the surfaces of the articles, for removal of such contaminants by the prevailing suction.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a somewhat diagrammatic front view of an apparatus according to the present invention; and

FIG. 2 is a partially sectioned view of the apparatus of FIG. 1, on an enlarged scale.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in the drawing the novel apparatus in accordance with our invention comprises a brushlike first disk-shaped contact element 1 and a second hollow contact element 2 which is also disk shaped, with the elements 1 and 2 being juxtaposed with one another. The element 1 is located above the element 2 and mounted on a hollow shaft 3 which is in turn suitably mounted in a nonillustrated machine frame and whose upper open end communicates with the hopper 4. The lower open end of the shaft 3 is open at the center of the brushlike element 1 so that discrete articles which pass through the hopper 4 and the shaft 2, enter into space between the juxtaposed surfaces of the elements 1 and 2, as evident from FIG. 2.

A pulley Sis rigid with the hollow shaft 3 and via the pulley 5 and a belt 6, which is driven by a nonillustrated drive of conventio nal type, the hollow shaft 3 is rotated. In accordance with the invention the rotation is carried out in such a manner that the shaft 3, and thereby the element 1, rotate alternately in opposite directions. In other words, the shaft 3 will rotate first in one direction and then will rotate in the opposite direction, to thereupon again rotate in the one direction. How this is accomplished is well known in the art and requires no detailed discussion herein. The drive for effecting this is not a part of the present invention.

The hollow shaft 3 further carries a cam disk 7 with which a roller 8 is associated which is rotatably secured on a stationary holder member 9. A pressure spring 10 is located below the cam disk 7 surrounding a portion of the hollow shaft 3 and abutting against the hub 11 of a tilting lever carrying the entire device. The lower axial end face of the hub II is constructed as a cam track 12 on which a roller 13 rolls. The roller 13 in turn is rotatably secured in a holder 14 which is secured in turn on the hollow shaft 3 carrying the element 1. It will be evident that with this arrangement the element 1 is tilted or laterally shifted, a movement which is superimposed upon its rotation, and that additionally has superimposed upon the two movements a further third movement in direction towards and away from the upper surface of the element 2.

The element 2 has an upper wall 15 which is provided with sievelike perforations 16. The exposed surface of the wall 15 is covered, as evident from FIG. 2, with an airand dust-permeable fabric cover 18 of suitable material, the term fabric here applying not only to textiles but to other suitable materials. It is also possible to use other types of covers, for instance consisting of nylon or the like, as long as they are air and dust permeable so that dustlike powder removed from the discrete articles 17, that is the capsules, can be drawn therethrough.

A funnel-shaped housing 21 surrounds at least the element 2 and, because it is larger in diameter than the element 2, the latter is secured in position by spacing members 22 which con nect it with the funnel-shaped housing 21. The housing tapers downwardly away from the element 2 which latter is provided with a suction aperture 19 at its bottom which is located so as to be coaxial with the hollow shaft 3. A conduit 20 connects the suction opening 19 with the diagrammatically illustrated suction means.

The bottom region of the housing 21 is provided with an outlet opening 23 which faces upwardly towards the element 2 so that cleaned capsules 17 which tumble over the edge of the element 2 as shown in FIG. 2, will fall into this outlet opening 23 to be convered away thereby into a collecting container 26. Proximal to the outlet opening 23 is an aperture 24 facing transversely to the direction of downward movement of the capsules l7, and the aperture 24 is connected via a conduit 25 with the suction means S.

As evident from the drawing, particularly from FIG. 2, capsules 17 introduced into the hopper 4 pass through the hollow shaft 3 and enter through the open outlet end of the hollow shaft 3, and the corresponding aperture in the element 1 which is provided at the center of the element 1 and free from bristles, so as to become deposited on the cover 18 of the upper wall of the element 2. Because of the up and down movement of the element 1, combined with the rotary movement thereof in alternately opposite directions and the tilting or lateral movement of the element 1, these capsules 17 are moved from the center of the elements 1 and 2 in radially outward direction to the edge of the element 2 and then tumbled over this edge to fall in the housing 21 through the outlet opening 23 thereof into the receptacle 26.

The movement of the element I, particularly the alternately opposite direction of rotation thereof, results in contacting of the entire surface of the capsules 17 by the bristles of the element 1 in such a manner than an excellent cleaning and polishing effect is obtained, removing adhering particulate contaminants from these surfaces. Because the suction aperture 19 is located directly below the outlet opening of the hollow shaft 3, any particulate contaminants which loosely adhere to the surfaces of the capsules 17 are withdrawn even as the capsules approach the elements 1 and 2, that is before they undergo treatment by the same. The suction is of course stronger at the center of the element 2 than towards the edges thereof. As a result it is necessary only to remove the more strongly adhering particulate contaminants from the surfaces of the capsules 17 by contact with the bristles of the element 1 and the cover 18 ofthe element 2.

The composite movement of the element 1 provides for excellent cleaning of the capsules over their entire surfaces, including their end faces if they are elongated. The movement of the element 1 up and down, that is in direction towards and away from the upper wall 15 of the element 2, assists the admission of additional capsules 17 and the movement of the capsules radially outwardly to the edge of the element 2.

it should be understood that it is not absolutely essential for the element 1 to be constructed as a brushlike element with bristles, because other solutions are also possible. It is also not to be considered limiting that in the illustrated embodiment the element 2 is constructed so as to be stationary. However, in this particular construction, and by cooperation of the bristles of the element 1 with the fabric cover 18 of the element 2 the particulate contaminants removed from the surfaces of the capsules 17 is prevented from adhering to the bristles of the element 1 and is forced to fall out between the bristles so that it can be removed by the prevailing suction. As a result of this the brushlike element 1 need be removed only infrequently for cleaning purposes. The airand dust-permeable cover 18, on the other hand, assures that the capsules will not be scratched during their movement while they are being processed, and on the other hand it makes it possible to have a single upper wall 15 with openings of one predetermined size, rather than necessitating the provision of exchangeable separate upper walls with openings of different sizes to accommodate differently dimensioned articles.

The suction aperture 24 which is provided proximal to the outlet opening 23 of the housing 21 serves to withdraw such pulverulent matter as may possibly issue from cracked or opened capsules, that is such capsules which might be cracked or opened during the polishing process, and to prevent it from entering into the receptacle 26 where it would again contaminate the already cleaned capsules 17. However, this is merely an added safety factor because ordinarily any such pulverulent contaminants will be removed by suction through the apertures in the wall 15 and through the cover 18. Of course, additionally the suction exerted through the suction aperture 24 serves to withdraw empty half-capsules which might have become emptied when their contents escaped, or capsules which inadvertently were not filled at all, from the cleaned capsules which pass through the outlet opening 23 in the receptacle 26.

The present invention provides for rapid and effective cleaning and polishing of the surfaces of discrete articles, of which the capsules 17 are merely representative, in a simple. effective and inexpensive manner without requiring significant technological expenditures for the construction of the machine and without requiring much personal supervision.

it will be appreciated that if the problem exists that the particulate contaminants especially tenaciously to the surfaces of the articles to be cleaned and polished, two or if necessary even several of the apparatuses according to the present invention may be arranged in succession so that the articles will successively pass through all of such apparatuses. In this case the elements 1 in the different apparatuses may be provided with different bristles or the like, and/or the elements 2 may be provided with covers 18 of different materials, different weave, mesh or the like. I

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in the polishing and cleaning of discrete articles, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

We claim:

1. An apparatus for cleaning and polishing the surfaces of discrete articles for removing particulate contaminants therefrom, comprising feed means for feeding the discrete articles in a predetermined path; processing means interposed in said path for subjecting the advancing articles to a brushing action so as to loosen particulate contaminants adhering to the surfaces of said articles, said processing means comprising hollow shaft means surrounding a portion of said predetermined path and having an inlet communicating with said feed means, a pair of superimposed disk-shaped elements extending transversely of the longitudinal axis of said hollow shaft means and forming with one another a gap therebetween defining another portion of said path, an outlet opening in said hollow shaft means communicating through the central region of one of said elements with the central region of said gap, bristles provided on one of said elements and extending across said gap in the direction towards the other element; moving means for effecting movement of at least one of said elements with reference to the other, said movement being at least in part rotational about the longitudinal axis of said hollow shaft means; and suction means communicating with said gap so as to remove loosened particulate contaminants from said articles.

2. An apparatus as defined in claim 1; said moving means being operative for effecting movement of said one element relative to the other element in such a manner that said one element tilts, rotates in alternately opposite directions and moves towards and away from the other element.

3. An apparatus as defined in claim 1, wherein said elements are located in two superposed at least substantially horizontal planes, and wherein said one element is located above said other element.

4. An apparatus as defined in claim 3, wherein said other element is hollow and has an air-permeable surface facing said brush; said suction means communicating with the interior of said other element.

5. An apparatus as defined in claim 4, wherein said other element is stationary.

6. An apparatus as defined in claim 4, wherein said other element comprises a perforate surface, and an airand dustperrneable cover layer on said perforate surface.

7. An apparatus as defined in claim 6, wherein said cover is a fabric cover.

8. An apparatus as defined in claim 4; and further comprising a housing surrounding both of said elements and converging in direction downwardly away therefrom for receiving and downwardly conveying polished articles.

9. An apparatus as defined in claim 8, wherein said housing has a lower end portion provided with a first aperture facing upwardly for entry of said polished articles thereinto, and a second aperture transversely to said first aperture; and conduit means connecting said second aperture with said suction means. 

1. An apparatus for cleaning and polishing the surfaces of discrete articles for removing particulate contaminants therefrom, comprising feed means for feeding the discrete articles in a predetermined path; processing means interposed in said path for subjecting the advancing articles to a brushing action so as to loosen particulate contaminants adhering to the surfaces of said articles, said processing means comprising hollow shaft means surrounding a portion of said predetermined path and having an inlet communicating with said feed means, a pair of superimposed disk-shaped elements extending transversely of the longitudinal axis of said hollow shaft means and forming with one another a gap therebetween defining another portion of said path, an outlet opening in said hollow shaft means communicating through the central region of one of said elements with the central region of said gap, bristles provided on one of said elements and extending across said gap in the direction towards the other element; moving means for effecting movement of at least one of said elements with reference to the other, said movement being at least in part rotational about the longitudinal axis of said hollow shaft means; and suction means communicating with said gap so as to remove loosened particulate contaminants from said articles.
 2. An apparatus as defined in claim 1; said moving means being operative for effecting movement of said one element relative to the other element in such a manner that said one element tilts, rotates in alternately opposite directions and moves towards and away from the other element.
 3. An apparatus as defined in claim 1, wherein said elements are located in two superposed at least substantially horizontal planes, and wherein said one element is located above said other element.
 4. An apparatus as defined in claim 3, wherein said other element is hollow and has an air-permeable surface facing said brush; said suction means communicating with the interior of said other element.
 5. An apparatus as defined in claim 4, wherein said other element is stationary.
 6. An apparatus as defined in claim 4, wherein said other element comprises a perforate surface, and an air- and dust-permeable cover layer on said perforate surface.
 7. An apparatus as defined in claim 6, wherein said cover is a fabric cover.
 8. An apparatus as defined in claim 4; and further comprising a housing surrounding both of said elements and converging in direction downwardly away therefrom for receiving and downwardly conveying polished articles.
 9. An apparatus as defined in claim 8, wherein said housing has a lower end portion provided with a first aperture facing upwardly for entry of said polished articles thereinto, and a second aperture transversely to said first aperture; and conduit means connecting said second aperture with said suction means. 